Thermal electric-circuit controller



Feb. 16 1926. 1,573,187

G. w. oKl-:EFFE

THERMAL ELECTRIC CIRCUIT CONTROLLER Filed April 28, 1922 ew/WWK \\\\\\\\\v Wm me?? or,

Patented Feb. 16,v 1926.

UNITED STATES PATENT OFFICE.

GEORGE W. OKEEFFE,IOF DORCHESTER, MASSACHUSETTS, ASSIGNOR, BY MESNE AS- SIGNMENTS, TO CONDIT ELECTRICAL MANUFACTURING CORPORATION, OF BOS- TON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS. y i

THERMAL ELECTRIC-CIRCUIT CONTROLLER.

Application filed April 28, 1922. Serial No. 557,055.

To all whom 'it may concern:

Be it known that I, GEORGE 1V. OKEEFFE,

a citizen of the United States, residing at Dorchester, in the county of Suffolk and State of Massachusetts, have invented an Improvement in Thermal Electric-Circuit Controllers, oi which the following is a specification. Y

This invention relates to thermal electric circuit controllers of the tyne wherein the thermally expansible element, and associated elements, are contained Within a tubular enclosing'casing,'and is adapted to be re'- ceived in spring clips in a manner similar to a. cartridge type enclosed electric fuse.

An object of this invention is generally to improve theI construction and opera-tion of controllers of the above type and, specifically, this invention is intended as an iirprovement on the invention disclosed in my co-pending application filed April 28, 1922, Serial No. 557,054.

Fig. 1 is a side View of the thermal electric circuit controller embodying theA invention.

Fig. 2 is an axial sectional elevation of the controller as mounted in spring clips.

Fig. 3 is a plan view of the controller.

Fig. 4 is a sectional elevation of the controller without the electrical heating element.

Fig. 5 is a left hand end View of the controller of Fig. 1.'

Fig. G is a right troller of Fig. 1, i

Fig. 7 is a cross-section of the controller along lines 7-7 of Fig. 2 with the thermal element and fixed contact member arranged to control a normally closed control circuit.

Fig. 8 is a view similar to Fig. 7 with the parts arranged t0 control a normally open circuit.

Fig. 9 is a sectional elevation of an end cap with attached thermal element.

Fig. 10 is a side view of the insulating plu for the fixed terminal member. Fig. 11 is a plan view of an end cap and illustrates the slot in the side Wall thereof.

Fig. 12 is a plan view of the tubular casing and illustrates the slot in the end therehand end view of the concentricall Fig is a diagram of a typical control circuit including the circuit controller.

Fig. 14 is a transverse sectional view through a convolution of the thermal element and illustrating more particularly the construction of the thermostatic material composing the element. i

As here shown, the thermal electric cir-v cuit controller embodying the invention includes the tubular enclosing casing 10 of insulating material and the end caps 11 and 12 which are received on the ends of and enclose said casing and, in the final assembly of the controller, are adapted, preferably, to be permanently secured to the casing by suitable means, as by crimping them over the ends of the casing.

The thermally expansible element may comprise the tubular coil 13 of thermostatic or other suitable expansible material havingv the inner end portion 14 thereof extended laterally of the coil and provided with the contact points 15 disposed on opposite sides of said end portion andadapted for engagement with a fixed terminal or cont-act member hereinafter to be described. Said and electrically connected With the en .suitable'means and, as here shown, the outer end portion 16 is secured by suitable means,

'as solder, to the tube 17, which latter is inserted within .the outer. end of said coil. Said tube may have the reduced outer endportion 18 which is received Within an ecdisposed aperture 19 in the end Wall of t e end cap 11; and said-end ortion may be expanded over the end wall to.

secure the thermal element permanently tov and in electrical connection with the end cap.

'lhe thermostatic material comprising said expansible element may comprise a strip or sheet composed of two metals having dissimilar expansion coefiicients and united together in any suitable manner to forni, in effect, a single sheet or strip having. marked susceptibility to temperature variations. Fig. 14' illustrates a cross-sectional view taken through one of the convolutions of the thermal element and illustrating the dissimilar metals n: and y.

It is an object of this invention to prothe controller and to which a lead of the control circuit is adapted to be connected. For this purpose, a plug 20 of insulating material is snugly received within and is supported by the casing 10 in front of the end cap 12; and said plug-may have the peripheral outstanding .flange 21 received between the end of the casing 10 and the end cap 12 whereby to hold the plug axially in position within the casing.Y Said plug is formed with the lateral extension 22 which projects externally substantially beyond the casing and the end cap 12 and forms an external insulating support for the fixed contact member. The side wall of the end cap 12 is formedl with the recess 23 in which said extension is received and the side wall of the enclosing casing 10 is formed with a similar recess 24CV in which said extension is also received; and said extension is preferably snugly received in both aligned recesses whereby to lock said plug and end cap and casing together so far as relative ,angular motion is concerned.

he fixed 'terminal' or contact member comprises the L-shaped bar 25 imbedded within said plug 2() beneath the lateral surface thereof and having one leg 26 extended laterally and externally beyond the casing through the extension 220i:l the plug. VConnecting means, as the screw 27, may be carried by said leg 26 beyond the casing for connection with a lead of the control circuit. Said bar 25 is also formed with the leg 28 which is extended longitudinally within the casing 10 adjacent and in cooperative relation with the movable end of the thermal element 13. Said leg 28 may have an adjustable contact point, as the screw 29, threaded in said leg which is adapted to be engaged by one or the other of the contact points 15 to control the control circuit including the fixed contact member and thermal element.

In Fig. 7 the movable end-portion 140i the thermal element and the contact -member are arranged to control a normally closed control circuit and the thermal element is arranged to move angularly toward the left under the influence of heat and break the control circuit. In Fig. 8, the arrangement is for a normally open control circuit and the thermal element is arranged to move toward the left when heated and close the control circuit.

The free or inner end of the tubular thermal element is rotatably supported in position by the insulating cylindrical projection 30 of the insulating plug 2O which is arranged co-axially with said thermal element and is received loosely therein.

The controller as described is adapted to be assembled as a unit and yelectrical heatyhole 41.

ing elements for the thermal element are adapted subsequently to be inserted; and the particular heating element to be inserted will depend upon the current value at which the controller is desired to operate.

The electrical heating element for the 'thermal element may be in the form of an electrically conducting rod 35. Said rod is disposed within the tubular thermal element and in heat-imparting relation therewith.

One end of the rod may he received lwithin the passage 86 in the tube 17 of the thermal element and the other end may be extended through a passage 37 in the insulating plug 20 and an aligned aperture 88 in the end cap 12. The heating element may be permanently secured in place and'in electrical connection with said end caps 11 and 12 by suitable means as solder applied to the end cap over the ends of said heating element.

' The character of the heating element may vary for the different values of current at which the controller is desired to operate. For relatively large values of current, the heating element may have relatively low resistance and, for lower values of current, a higher resistance. For extremely low values of current, the heating element may bel a carbon rod, not necessarily shown.

The contact point 29 of the fixed contact member 25 may be adjusted from without the casing by the insertion of a suitable tool through one or the other of the holes 40 in the side wall of the casing 10; and the relative position of the fixed contact member and movable end of the thermal element may be inspected through the peep All ,holes may be permanently covered bya suitable seal, as the label 42, after the final adjustment is made.

In the assembly of the component parts of the controller it is to be noted that, as the extension 22 of the insulating plug 20 locks together said plug with its fixed contact member, the end cap 12 and the enclosing casing 10, the initial adjustment of the contacts may be made by rotating but a single member, the end cap 11 with its thermal element, in the proper direction.

The end cap 11 and the casing 10 may have Witness marks A and B respectively, or other suitable indicia, which may be brought into alignment to indicate the proper operative relation ot' the relatively movable contact members concealed within the casing.

- The controller may be inserted in, and for the protection of, a power circuit 50, see Fig. 13, here shown as having the motor 51 connected therewith, and the fixed Contact member 25 of the controller and the thermal element are connected with and arranged to control the control circuit 52 of the switch to effect the opening' ot' said switch when the current in the power cirlao navals? ing the thermal element.

l claim:

Y l. A thermal electric circuit controller includingthe combination of an enclosing casing, metal end caps disposed on the ends' of the casing, a movable thermally expansible element contained Within the casing and an insulated fixed contactmember disposed Within the casing in operative relation With said thermally expansible element and extended laterally beyond the casing and through and insulated from one of said end caps and having connecting means for a circuit lead carried by its extended end.

2. A thermal electric circuit controller including the combination of a tubular enclosing casing, metal caps on the ends of the casing, a movable thermally expansible element disposed Within the casing., and .an insulated fixed contact member disposed Within said casing in 'cooperative relation with 'said thermally expansible element and extendedaxially Within saidcasing toward one end thereof and haulingy a terminal portion extended laterally through the tubular casing and the side Wall ofl and insulated from an end cap and having connecting means for a circuit lead carried by its extended end,

3. A thermal electric circuit controller including the combination of an enclosing casing, an end cap on one end of said casing, a thermally expansible element disposed Within said casing, an insulated fixed contact member disposed in operative relation with said thermally expansible element, and

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means to lock together said casing and end 'cap and contact member in fixed relation' 4f. A thermal electric circuit controller in.-l cl'uding the combination ot an enclosing casing, an end cap on one end of said cas-I means to lock said casing. and end cap and.

contact member in 'fixed relation comprising an insulating support tor said contact member extended laterally through aligned recesses in said casing and end capa 5 A thermal electric circuit controller' including the combination of an enclosing casing, an end cap on one end ol said cas ing, a thermally enpansible element within said casing, an insulated. idxed con tact member disposed in operative relation with said therfnall expansible element, and means to loclr saidy casing and end Contact member in fixed relation comprising an insulating support Jlor said iixed contactI member extended laterally through aligned recesses in the side wall at the end et said casing and in the side Wall ot said end capa 6. A thermal electric circuit controller including the combination of an enclosing casing, an end' cap on one end of said casing, a thermally expansible element disposed Within said casing, an insulated fixed contact member disposed in operative relation vvith said thermally expansible element, and

.means to lock said casing and end cap and contact member in xed relation comprising an insulating support for said fixed contact member extended laterally through aligned recesses in the side Wall at the end of said casing and in the side Wall of said end cap, an end cap on the other end of said casing, and electrical heating means Vdisposed in heating relation with said thermally expansible element and electrically connecting said end caps. n

7. A thermal electric circuit controller including the combination of an enclosing casing, an end cap on one end of said casing, a thermally expansible element disposed Within said casing, an insulated fixed contact member disposed in operative relation with said thermally expansible element, and means to lock said casing and end cap and Contact member in fixed relation comprising an insulating plug carrying said xed contact member received in the end of and supported by said casing, said insulating plug having a lateral projection which extends laterally through alignedI passages in said casing and end cap,

8. A tlermal electric circuit controller including the combination of an enclosing casing, an end cap on one end of said casing, a thermally expansible element disposed Within said casing7 an insulated fixed contact member disposed in operative relation with said thermally expansible element, and means to lock said casing and end cap and said. contact member in fixed relation com an insulating plug carrying said xed contact member received in the end of and supported by said casing, said insulating tier.

a t'iermally expansible element disposed ivithi i casing in operative relation wit"- sai n contact member, and adjustable suppemeans for said expansible element A thermal electric circuit controller including the combination ci an enclosing cosx an end cap on the end thereof, an insulated lixed contact menber disposed lll@ Within the casing andl extended externally thereof, and means holding all in fixed relation, a thermally expansible element cl1svposed Within said casing in operative relation with said fixed contact member, and adjustable supporting means 'for said expansible element comprising a second end cap bearing Said expansible element rotatably received on the end of said casing.

ll. A thermal electric circuit controller including the combination of an enclosing casing, an end cap on the end thereof, an, insulateol xeol contact member disposed within the casing and extended externally there- `said fixed contactrmember, and adjustable supporting' means for said expansible element comprising a second end capv havlng said expansible element rotatably received `on the end of said casing and electrical heating meansI disposed in heating relation with said thernally expansible element and electrically connected With said end caps.

YIn testimony whereof, I have signed my name to thisspecication.

GEORGE W. OKEEFFE. 

